DFRobot Gravity: Digital Water Flow Sensor For Arduino - 1/8"

The Water Flow sensor measures the rate of a liquid flowing through it. The YF-S401 water flow sensor consists of a plastic valve body, flow rotor and hall effect sensor. It is usually used at the inlet end to detect the amount of flow. When liquid flows through the sensor, a magnetic rotor will rotate and the rate of rotation will vary with the rate of flow. The hall effect sensor will then output a pulse width signal. Connect it to a microcontroller and you can monitor multiple devices such as your coffee maker, sprinkler or anything else, and control the water flow rate to suit your needs!

Note:
*A 6 mm hose is recommended
*Avoid unit contact with corrosive chemicals
*The unit must be installed vertically, tilted no more than 5 degrees
*Liquid temperature should be less than 120 C to avoid damage to unit